In the area of biodefense, current systems are centered on the detection of smaller prioritized sets of high-risk pathogens, rather than testing for a much broader spectrum of organisms; a new detection method from Lawrence Livermore allows not only the identification of the biological pathogens on a priority screening list, but also any other already-sequenced bacteria or virus in a sample that first responders, doctors, or regulatory agencies might not have been expecting to find, including possible novel or emerging pathogens

Law enforcement authorities seeking to detect bioterrorism attacks, doctors diagnosing diseases, and regulatory agencies checking product safety may find a new ally in a Lawrence Livermore National Laboratory (LLNL) detection technology. The advance, known as the Lawrence Livermore Microbial Detection Array (LLMDA), could enable law enforcement, medical professionals and others to detect within twenty-four hours any virus or bacteria that has been sequenced and included among the array’s probes.

Developed between October 2007 and February 2008, the LLMDA detects viruses and bacteria with the use of 388,000 probes that fit in a checkerboard pattern in the middle of a one-inch wide, three-inch long glass slide.

The current operational version of the LLMDA contains probes that can detect more than 2,000 viruses and about 900 bacteria. “The ability to detect the major bacterial and viral components of any sample can be used in countless different ways,” said Tom Slezak, LLNL’s associate program leader for Informatics. “This is important because it fills a cost-performance gap that is relevant to many missions: biodefense, public health and product safety.”

In the area of biodefense, current systems are centered on the detection of smaller prioritized sets of high-risk pathogens, rather than testing for a much broader spectrum of organisms. “The LLMDA allows us to not only identify the biological pathogens on a priority screening list, but also any other already-sequenced bacteria or virus in a sample that you might not have been expecting to find, including possible novel or emerging pathogens,” Slezak said.

Current plans call for the detection array to be evaluated for operational bioforensic use at the Frederick, Maryland-based National Biodefense Analysis and Countermeasures Center of the U.S. Department of Homeland Security.

As the cost of the array is reduced, the LLMDA technology could be used to improve public health diagnostics, Slezak said, adding that dozens of bacteria and viruses can be detected in a single test from the entire spectrum of sequenced organisms.

One advantage of the Livermore array is that it provides researchers with the capability of detecting pathogens over the entire range of known viruses and bacteria. Current multiplex polymerase chain reaction (PCR) techniques can at most offer detection from among 50 organisms in one test.

In April, in a Journal of Virology article, Livermore researchers working with a scientist from the San Francisco-based Blood Systems Research Institute said they used the LLMDA technology to confirm the presence of an apparently benign pig virus in a